Laparoscopic gallbladder surgery is very much known to the biliary surgery specialist, in such a way that the description of this technique will not be expressed but it is necessary to say that four micro incisions on the upper part of the abdomen in accordance with biliary topography are made in places, which for carrying out the surgical steps better are known as the most convenient. In the micro incisions and through the abdominal wall some 5 mm. to 10 mm. diameter size cannulae are placed and, through them a variety of instruments are introduced which the surgeon manipulates from outside the patient's body, being guided by looking at images on a monitor transmitted from the abdominal cavity by a video camera inserted into the abdominal cavity.
For performing surgical cholangiography it is necessary to follow some surgical steps, which at present are quite similarly regulated in most surgical centers. In short they are:    1-Surgical search of the cystic duct.    2-Dissection of cystic duct for its perfect identification.    3-Putting either a ligation or clamping or clipping the cystic duct near the gallbladder neck.    4-Placing the cystic duct in tension by grasp-and-traction of gallbladder with suitable instruments.    5-Making a cross micro incision in the cystic duct thereby reaching its inner diameter through a small opening it is possible to enter into the cystic duct.    6-Inserting either a blunt tip rigid needle or a flexible catheter in the cystic duct opening which allows the injection of a radiopaque medium.    7-Ligation, clamping or clipping the cystic duct very closely to the cystic opening embracing the needle or catheter already introduced in it, thereby avoiding their displacement or escape of injected liquid outside the duct, thereby causing a dark spot in the biliary duct region for X-rays.    8-Injection of a radiopaque medium.    9-Taking the X-rays.    10-Extraction of the ligation, clamp or clip, which is pressing both the duct and needle or catheter.    11-Extraction of needle or catheter. This is the last step of the cholangiography.
The instrument we are speaking about takes part in steps numbered 6, 7, 8, and 10, therefore, with reference to the execution of these steps, the present state of the technique and its disadvantages will be described.
Step 6 is carried out introducing the catheter or needle into the abdominal cavity through one of the cannulae which have been placed during previous steps; therefore it is necessary first to extract the instrument which had been inserted in it. Another way is using a new cannula, which is situated in an abdominal place that allows the catheter or needle to be more easily oriented toward the cystic duct opening. A catheter is very difficult to insert in the cystic duct opening except if the duct inner diameter is dilated. This fact and other causes, which are unnecessary to mention now, make the use of catheters rare. Mostly the duct diameter is decreased, normal or little dilated and then the employing of a needle makes the procedure easier. However, using a cannula, placed during previous steps, the abdominal place where it was placed makes this step very difficult to carry out because it is not possible to get a needle-duct wide-incidence angle so that the needle and duct be almost parallel with each other. This is very important for allowing the needle tip inserted in the cystic duct opening, to slide 5 to 10 mm. into the duct without endangering the diametrically opposite wall. This problem is minimized putting a new cannula such as mentioned above but; even so employing the normal straight needle, this step is not easy, it is slow and the risk for injuring the duct wall is present.
Step 7 is carried out putting a metal clip using a suitable forceps: an instrument inserted in a cannula is brought out and, through this cannula the forceps carrying the clip between its jaws is introduced into the abdominal cavity. For easier understanding, we can say the clip is the same as a small, metallic U letter. Clips were made for shutting some vein or artery off completely by strongly driving the forceps handles and reaching the end of its running. In such a way, both arms of the clip being around the vessel, it is completely flattened. Going back to step 7, we have to remember it is necessary for avoiding both the needle to slide and the injected radiopaque medium to escape outside the duct. The clip is carried on the forceps so that the cystic duct remains between its parallel arms, and then with his skilful hand the surgeon operates the forceps with very controlled movements and force in such a way that the cystic duct walls are sufficiently pressed against the needle to avoid both the sliding of the needle and the escaping of some liquid; but not so much as to making the clip extraction difficult. The clip-applying forceps has not been designed for being used in this way; therefore, step 7 will be effective in accordance with both experience and ability of the surgeon, as well as the tactile and pressing sensibility of his hand and also according to the functional state of the forceps. This is a resterilizeable metallic several-joint instrument and after each surgical operation must be washed and lubricated and then sterilized. Sometimes this procedure is not perfectly carried out and the forceps joints get hard and then it is possible for the surgeon to have a wrong appraisal of how much pressure is reached on the arms of the clip. These facts cause step 7 not to be absolutely trusted and therefore it is necessary to control if the clip correctly presses the needle. For this control the surgeon gradually slackens the pressure of the forceps on the clip; at the same time with his other hand he slightly attempts the needle to slide, holding the clip and forceps relative position so as to press with higher force if the clip is slack and then repeating the procedure. All of this obviously prolongs the surgical time. For carrying out step 8 a flex catheter connected with the needle on one of its endings and with a syringe on its second ending is employed. Saline liquid is injected watching if it escapes outside of the duct. If this happens we must change the clip for getting a better occlusion of the duct and then it is necessary to vacate some other cannula and through it a forceps slides for making traction of the clip. The forceps carrying the clip is brought out of the abdominal cavity and then, now carrying a new clip, the forceps is introduced to press the clip around the cystic duct. The clip is controlled in accordance to step 7 and again the saline liquid injection is made for controlling whether the liquid escapes or not and, if this is OK, the contrast medium is finally injected. Although the clip has been correctly mounted, the increased pressure of the liquid while it is injected into the cystic duct could cause the liquid to escape. This happens when the needle fits the cystic duct loosely: the parallel arms of the clip press the duct walls against the needle without surrounding them but the arms remain parallel in such a way that duct section walls at the clip zone are partially separate having a free communication between the lumen duct and outside through the duct opening.
Step 10 is the clip extraction and it is carried out getting a forceps into the abdominal cavity which catches the clip handle and by traction separates it from the duct, being, together with the forceps, carried outside. If the clip is slackly mounted its extraction in general is not difficult but, when it is strongly pressed it is necessary to traction strongly and, it is possible, at times that the clip and the cystic duct are separated; the forceps makes an uncontrolled movement which following both direction and sense of the traction are able to injure nearby organs. Whether the clip was slack or not, it is sometimes possible, along the extraction way, for the clip to fall in the abdominal cavity, being necessary to catch it again and get it outside; but if the clip is covered by bowels, then it will not be easy to find it, however the surgeon must look for it and get it outside to avoid future injuries of organs.
Several devices and instruments for overcoming the above said difficulties have been thought up. One of them does not employ the clip for fastening the cystic duct and needle, a forceps is employed, which directly presses the duct and needle getting a correct fix of them and an easy extraction of the forceps, but the forceps being radiopaque can obscure visibility of the biliary duct region for X-rays if the forceps remains between the X-rays and the biliary duct region. Sometimes this fact happens, then it is necessary to change the forceps position and the X-rays study must be repeated, meaning waste of time.
Kumar noted that reasons for the high failure rate of the cystic duct cannulation may be attributed to the narrow and tortuous anatomic structure of this duct and in 1993 he presents (U.S. Pat. No. 5,224,931) an instrument having a forceps and a side channel for introduction of a catheter, which is inserted in the gallbladder infindibulum (also known as pouch of Harmann). Medical reasons disqualify as a first election the option of cannulating the infundibulum instead of the cystic duct. In 1994 Clement et al. (U.S. Pat. No. 5,350,384) presented an instrument which also combines a forceps and a side channel for introduction of a catheter, which for inserting into the cystic duct must be obliquely deflected and, this act as also both the flexibility of the catheter and the anatomic cystic duct characteristic (the valves, the narrowness and the tortuousness of its inner diameter) sometimes make the catheter sliding difficult
In 1996 Exconde et al. (U.S. Pat. No. 5,496,310) presented an instrument for performing cholangiographys through the cystic duct but it had a complicated design and low advantages. These inventions and others also patented do not overcome the whole afore mentioned difficulties in the surgical steps. Every one of them being a metallic instrument has a jaw mechanism which is driven through many joints and because of the high cost they do not have to be discarded so, they must be resterilized and this act makes them functionally less safe.
One object of this invention is to provide a suitable instrument for performing surgical cholangiography associated with either conventional or laparoscopic cholecistectomy and also allowing for the reduction of time at present required for this surgical procedure.
Another object is to provide an instrument, which reduces the risk for opening the cystic duct during cannulation by the needle.
Another object is to provide an instrument which allows the needle introduced in the cystic duct to remains fastened avoiding its sliding and besides avoiding the injected liquid to escape outside the duct.
Another object is to provide a safe instrument which allows injecting the contrast liquid directly being unnecessary to previously control escapes using the injection of saline liquid.
Another object is to provide an instrument which allows an easy extraction of the needle fastening without the risk of injuring nearby organs because of uncontrolled movements.
Another object is to provide an instrument with a simple design, without many joints and easy handling and whose effectiveness does not depend on previous surgeon experience.
Another object is to provide an instrument which allows to be driven from outside the body, is introduced in the abdominal cavity through a very flexible, small diameter and thin cannula that is inserted together with a conventional trocar crossing the abdominal wall.
Another object is to provide an instrument whose design allows low cost construction and together with both the cannula and the trocar constitute a non-resterilizable kit.